Racial disparities in readmissions and site of care for major surgery

Abstract

Background: Racial disparities have been described in many surgical outcomes. We sought to examine whether these disparities extend to postoperative readmission rates and whether the disparities are associated with differences in patient mix and/or hospital-level differences.

Study design: National Medicare beneficiaries undergoing operations in 3 different specialties from 2006 to 2008 were examined: colectomy, hip replacement, and coronary artery bypass grafting (CABG) (n = 798,279). Our outcome measure was risk-adjusted 30-day readmission. We first used logistic regression to adjust for patient factors. We then stratified hospitals into quintiles according to the proportion of black patients treated and examined the differences in readmission rates between blacks and whites. Finally, we used fixed effects regression models that further adjust for the hospital to explore whether the disparity was attenuated after accounting for hospital differences.

Results: Black patients were readmitted more often after all 3 operations compared with white patients. The unadjusted odds ratio (OR) for readmission for all 3 operations combined was 1.25 (95% CI 1.22 to 1.28) (colectomy OR 1.17, 95% CI 1.13 to 1.22; hip replacement OR 1.20, 95% CI 1.14 to 1.27; CABG OR 1.25, 95% CI 1.19 to 1.30). Adjusting for patient factors explained 36% of the disparity for all 3 operations (35% for colectomy, 0% for hip replacement, and 32% for CABG), but in analysis that adjusts for hospital differences, we found that the hospitals where care was received also explained 28% of the disparity (35% for colectomy, 70% for hip replacement and 20% for CABG).

Conclusions: Black patients are significantly more likely to be readmitted to the hospital after major surgery compared with white patients. This disparity was attenuated after adjusting for patient factors as well as hospital differences.